Conveyance system for web of packaging cushions

ABSTRACT

A conveyance system comprises a production machine for manufacturing a web of packaging cushions, a duct downstream from the production machine, a blower to provide an air flow through the duct to apply a conveyance force for conveying the web of packaging cushions, and a friction contact area downstream from the production machine and upstream from the duct entrance. The web of packaging cushions passes beneath and contacts the friction contact area to create a friction force opposing the conveyance force so that the conveyance force is not transmitted along the web of packaging cushions to the production machine.

BACKGROUND

The present invention relates to conveyance systems for packagingcushions.

SUMMARY

An embodiment of the invention is directed to a conveyance system 10 forconveying a web of packaging cushions 20. The system comprises aproduction machine 12 capable of manufacturing the web of packagingcushions. A duct 14 is downstream from the production machine. The ducthas an entrance through which the web of packaging cushions can be drawnfrom the production machine into the duct. A blower 16 provides an airflow through the duct to apply a conveyance force to the web forconveying the web of packaging cushions through the duct. A frictioncontact area 18 downstream from the production machine and upstream fromthe duct entrance is arranged so that (i) the web of packaging cushionspasses beneath and contacts the friction contact area as the web ofpackaging cushions passes from the production machine to the ductentrance and (ii) the contact between the web of packaging cushions andthe friction contact area creates a friction force opposing theconveyance force so that the conveyance force is not transmitted alongthe web of packaging cushions to the production machine.

The conveyance system may be useful to make and deliver webs ofpackaging cushions to one or more locations remote from the productionmachine 12 while also damping or averting the conveyance force fromtransmission upstream along the web of packaging cushions to theproduction machine. This may help avoid the conveyance force fromotherwise potentially adversely affecting the operation of productionmachine 12.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective representative view of system 10, an embodimentof the present invention.

FIG. 2 is a perspective representative view of a friction contact areamat.

FIG. 3 is a representative view of a duct entrance having the mat of thefriction contact area partially removed.

FIG. 4 is a representative side view of a portion of system 10.

FIG. 5 is a representative side elevation view of system 10.

FIG. 6 is a representative side elevation view of system 10.

FIG. 7 is a perspective portion of the mat 42 of FIG. 1.

FIG. 8 is a representative view of system 60, an embodiment of thepresent invention.

FIG. 9 is a representative view of system 62, an embodiment of thepresent invention.

FIG. 10 is a representative view of system 66, an embodiment of thepresent invention.

FIG. 11 is a representative perspective view of an extended sheet ofinflated air-cellular cushioning material having inflated rows as a webof packaging cushions.

DETAILED DESCRIPTION

Embodiments of the present invention are conveyance system 10 (FIGS. 1,5-6), conveyance system 60 (FIG. 8), conveyance system 62 (FIG. 9), andconveyance system 66 (FIG. 10), which comprise production machine 12,duct 14, blower 16, and friction contact area 18. The conveyance systemmay be used to transport a web of packaging cushions 20 from theproduction machine 12 to a desired location.

Production Machine

Systems 10, 60, 62, and 66 comprise production machine 12 capable ofmanufacturing a web of packaging cushions. (FIGS. 1, 5-6, 8-10) The webof packaging cushions 20 may comprise an extended string of packagingcushions, for example, as illustrated in FIGS. 1, 5-6, and 8-10, or maycomprise an extended sheet (or connected sheets) of inflatedair-cellular cushioning material, for example, as illustrated in FIG.11. Where the web of packaging cushions comprises a string of packagingcushions, each cushion 22 of the string of packaging cushions may beconnected to at least one other adjoining cushion of the string. Thestring of packaging cushions may comprise air-filled cushions,foam-filled cushions, as well as cushions comprising other types ofpackaging materials. The web of packaging cushions may be useful in oradapted for packaging dunnage applications. The cushions 22 may have anaverage length 32 in the machine direction of, for example, at leastabout and/or at most about any of the following: 4, 8, 12, 14, and 16inches. The rows 64 may have an average length 32 in the machinedirection of, for example, from about 0.75 to about 2 inches. The web 20may have an average width 34 in the transverse direction of from about 8inches to about 20 inches. The web may have an inflated height of fromabout 1¼ inches to about 3½ inches.

The web of packaging cushions 20 may include perforations (notillustrated) periodically along the web, for example, between adjacentcushions 22 of the string, to facilitate separation of the web into websegments or into one or more individual cushions. “Perforations” as usedherein includes scoring or other lines of weakening adapted for thepurpose of facilitating separation of the web of packaging cushions.

Exemplary webs of packaging cushions are sold, for example, by SealedAir Corporation as strings of air-filled dunnage cushions under theFill-Air® family of trademarks and as extended sheets of cushioningmaterial under the NewAir I.B.® and Barrier Bubble® family oftrademarks. Exemplary production machines capable of producing a web ofpackaging cushions include those sold by Sealed Air Corporation (i)under the Fill-Air® 1000, Fill-Air® 2000, Fill-Air® NTS, and Fill-AirElite® trademarks for producing a string of air-filled packagingcushions and (ii) under the NewAir I.B.® 200 and NewAir I.B.® 600trademarks for producing an extended sheet of inflated air-cellularcushioning material. Further examples of useful webs of packagingcushions and the machines for making them are disclosed in U.S. Pat.Nos. 5,942,076; 6,598,373; 6,651,406; 6,804,933; 6,996,955; 7,231,749;7,273,142; 7,220,476; 7,165,375; and U.S. Patent Application Publication2006/0289108 A1, each of which is incorporated herein in its entirety byreference.

In the case of production of air-filled packaging cushions, theproduction machine may use as feed stock a web of sheet material thatthe machine folds, partially seals, inflates, and then finally seals thematerial to form the string of packaging cushions, as is known in theart. The machine may use as feedstock a web of sheet material that hasbeen partially converted by, for example, folding, sealing, andperforating, before the feedstock enters the machine, also as is knownin the art. Suitable materials for the sheet material include polymerplastics, such as thermoplastics, as is known in the art.

Production machine 12 defines a manufactured web outlet elevation 26,which is the elevation at which the creation of each new air-filledcushion 22 (FIG. 5) or inflated row 64 (FIG. 11) of the web of packagingcushions 20 is completed and supplied by machine 12.

Duct

A duct 14 is downstream from the production machine 12 so that the webof packaging cushions 20 manufactured at the production machine can bedrawn into the duct at duct entrance 28 (defined below). The duct 14 hasduct exit 30 through which the web of packaging cushions may leave theduct. The duct 14 may have multiple intermediate exits (not illustrated)between the entrance 28 and exit 30, as described in U.S. Pat. No.6,699,955, which was previously incorporated in its entirety byreference. The duct 14 may be configured for overhead conveyance of theweb of packaging cushions to desired locations, for example, to one ormore hoppers (not illustrated) located remotely from the productionmachine 12.

The duct may be made of any suitable material, such as metal, forexample steel (e.g., galvanized steel or powder-coated steel) oraluminum alloy (e.g., polished aluminum). The duct walls may have athickness of, for example, from about 0.03 to about 0.5 inches. The ductmay have a rectangular-shaped cross section, so that the width 36 of theduct may generally correspond to the width 34 of the web of packagingcushions, for example, being from about 1 to about 4 inches wider thanthe width 34 of the web. The height 38 of the duct may similarlycorrespond to the height of the web, for example, the height ofair-filled packaging cushion 22 or inflated row 64. The duct may have acircular cross section, for example having a diameter of, for example,from about 8 to about 12 inches.

Blower

Blower 16 provides the motive fluid of an air flow through the duct toapply a conveyance force (F₁) to the web for conveying the web ofpackaging cushions through the duct. (FIG. 5.) The outlet 40 of blower16 is connected to duct 14 so that the air flow created by blower 16 isin fluid communication with duct 14. The blower and duct combine to formin essence an ejector, having the air flow from the blower as the motivefluid that creates a low pressure zone that draws in and entrains theweb of packaging cushions. As used herein, the “entrance” of the ductmeans the region of the duct adapted for the convergence of the conveyedweb with the motive fluid provided by the blower.

Blower 16 has the capacity to create sufficient airflow in the duct toapply a conveyance force (F₁) to convey the web of packaging cushionsfrom the entrance 28 to the exit 30. (FIG. 5.) The blower may also havethe capacity to create sufficient airflow to apply the conveyance forceto lift the web of cushions to the overhead height of the ductconfiguration. If needed to provide sufficient air flow, for example inthe configuration of multiple intermediate exits, then the airflowthrough the duct may be supplemented by one or more booster blowers (notillustrated) located downstream from blower 16.

By way of example, useful blower airflow capacities may range from about550 to about 1,200 cubic feet per minute. A suitable blower is availablefrom W.W. Grainger Corporation under the model number 1TDU2 to providean airflow for an overhead conveyance of a string of Fill-Air® cushionshaving a cushion length in the machine direction of about 8 inches, atransverse width of about 12 inches, and a height of about 2 inchesalong a duct having a length of about 40 feet, a width of about 15inches, and a height of about 4.5 inches.

Friction Contact Area

The friction contact area 18 is downstream from the production machine12 and upstream from the duct entrance 28. The friction contact area 18is arranged so that the web of packaging cushions 20 passes beneath andcontacts the friction contact area as the web of packaging cushionspasses from the production machine 12 to the duct entrance 28. Further,the friction contact area 18 may be arranged relative to the productionmachine 12 and the duct entrance 28 so that the contact between the webof packaging cushions 20 and the friction contact area 18 creates afriction force (F₂) opposing the conveyance force (F₁) so that theconveyance force is not transmitted along the web of packaging cushions20 to the production machine 12. (FIGS. 1, 5-6, 8-10.)

The friction contact area 18 may be arranged relative to the productionmachine 12 and the duct entrance 28 so that the manufacture of anadditional length of the web of packaging cushions results in atemporary reduction in the amount of surface area of the web 20 thatcontacts the friction contact area—as illustrated in FIG. 6—so that thefriction force (F₂) is reduced and the web of packaging cushions 20advances downstream of the friction contact area 18 in an amountcorresponding to the additional length.

The friction contact area 18 may be arranged relative to the productionmachine 12 and the duct entrance 28 so that the manufacture of anadditional length of the web of packaging cushions increases the weightof the web between the friction contact area 18 and the productionmachine 12 so that: (i) the web hangs lower to reduce the amount ofsurface area of the web that contacts the friction contact area 18 (seeFIG. 6) and (ii) the conveyance force (F₁) overcomes the friction force(F₂) to advance the web of packaging cushions downstream.

The elevation 50 of the duct entrance 28 may be above the elevation 52of the friction contact area 18 taken at the lowest point of thefriction contact area. (FIGS. 1, 5, 6, and 9.) Alternatively, theelevation 50 of the duct entrance 28 may be below the elevation 52 ofthe friction contact area 18 taken at the lowest point of the frictioncontact area. (FIG. 8.)

The manufactured web outlet elevation 26 from which the manufactured webof packaging cushions passes may be above the elevation 52 of thecontact friction area 18 taken at the lowest point of the frictioncontact area. (FIGS. 1, 5, 6, and 8.) Alternatively, the manufacturedweb outlet elevation 26 may be below the elevation 52 of the contactfriction area 18 taken at the lowest point of the friction contact area.(FIG. 9.)

The elevation 52 of the contact friction area 18 taken at the lowestpoint of the friction contact area may be below either one or both ofthe following: (i) the manufactured web outlet elevation 26 and (ii) theelevation 50 of the duct entrance 28.

The length in the machine direction of the friction contact area 18 maybe longer than the average length 32 in the machine direction of theindividual packaging cushions or inflated rows that make up the web ofpackaging cushions. The length in the machine direction of the frictioncontact area 18 may be longer than the total average length 32 in themachine direction of a number of packaging cushions or rows selectedfrom any of at least and/or at most 2, 4, 6, 8, and 10.

The friction contact area 18 may be stationary.

The friction contact area 18 may comprise primarily a first material.The duct 14 may comprise primarily a second material, such as metal, forexample, aluminum alloy or any of the other duct materials discussedherein. “Primarily” in these contexts means that the surface arranged tobe in contact with the web of packaging cushions comprises more thanabout 50 weight % of the specified material. The first material of thefriction contact area may have a coefficient of friction (relative tothe web of packaging cushions) that is greater than the coefficient offriction of the second material of the duct (relative to the web ofpackaging cushions). For example, the first material may be elastomer,and the second material may be metal that has a lower coefficient offriction relative to the web of packaging cushions.

An exemplary primary material of the friction contact area 18 iselastomer, for example, selected from one or more of any of thefollowing: rubber (e.g., natural rubber), acrylonitrile/chloroprenecopolymer, acrylonitrile/isoprene copolymer, butadiene/acrylonitrilecopolymer, chlorinated polyethylene (“cPE”); chlorosulfonatedpolyethylene, ethylene ether polysulfide, ethylene polysulfide,ethylene/propylene copolymer (“EPC”), which includes copolymers ofpropylene and ethylene having a majority weight % content of propylene,ethylene/propylene/diene terpolymer (e.g., EPDM), fluoroelastomer,fluorosilicone, hexafluoropropylene/vinylidene fluoride copolymer,isobutene/isoprene copolymer, organopolysiloxane, acrylicester/butadiene copolymer, polybutadiene, polychloroprene,polyepichlorohydrin, polyisobutene, polyisoprene (natural or synthetic),polyurethane (polyester or polyether), polyurethane (polyether andpolyester), polyethylene-butyl graft copolymer, styrenic copolymers(e.g., styrene/butadiene copolymer, stryene/chloroprene copolymer, andstyrenic block copolymers, such as styrene/butadiene/styrene copolymer(“SBS”), styrene/isoprene/styrene copolymer (“SIS”),styrene/ethylene-butylene/styrene copolymer (“SEBS”),styrene/ethylene-propylene/styrene (“SEPS”), andstyrene/ethylene-propylene copolymer (“SEP”)), ethylene/unsaturatedester copolymer (e.g., ethylene/methyl acrylate copolymer,ethylene/methyl methacrylate copolymer, ethylene/ethyl acrylatecopolymer, ethylene/ethyl methacrylate copolymer, ethylene/butylacrylate copolymer, ethylene/2-ethylhexyl methacrylate copolymer, andethylene/vinyl acetate copolymer (“EVA”)), ethylene/(meth)acrylic acidcopolymer (i.e., the copolymer of ethylene and acrylic acid, methacrylicacid, or both), ethylene/alpha-olefin copolymers (“EAOs”) having anaverage density, for example, of at most about 0.912 g/cm³.

“Copolymer” as used in this application means a polymer derived from twoor more types of monomers, and includes terpolymers, etc. The monomerlisted first in the name of the polymer does not necessarily mean thatthat monomer is present in a majority amount (e.g., “ethylene/propylenecopolymer” includes copolymer having 85 weight percent propylenemonomer.)

The primary material of the friction contact area 18 may comprise atextile material, for example comprising primarily any of the following:(i) natural fiber, such as primarily any of cotton or wool, or (ii)synthetic fiber, such as primarily any of nylon, rayon, polyester, oraramid (such as Kevlar® brand aramid fiber). The primary material of thefriction contact area 18 may comprise primarily any of leather or corkmaterials.

The friction contact area may comprise primarily material having aconfiguration selected from any of the following: woven (as in somecarpets), non-woven (such as felt materials), tufted (as in somecarpets), hooked (as in some rugs), and molded (as is useful forthermoplastics).

The friction contact area may comprise a mat 42. The mat 42 may compriseany of the primary materials or configurations discussed above, and mayfurther comprise a substrate, for example of fiberglass or textilematerial, to provide strength to the mat. For example, mat 42 maycomprise a conveyor belt material, for example, such as that availablefrom Ammeraal Beltech Corporation under the FLEXAM EM 7/2 0+A34 D tradename.

The mat 42 may be supported by and/or attached to guide 46, whichpositions mat 42 so that the web of packaging cushions passes beneathand contacts mat 42 as the web passes from the production machine to theduct entrance.

The mat 42 may be removably attached, which means that the mat may berelatively easily removed from the system without damaging the mat orthe remainder of the system so that the mat may be readily replaced ifit wears to an unacceptable degree. For example, mat 42 may be attachedto system 10 by one or more snaps 44 or clips (not illustrated), or by ahook and loop material (not illustrated).

The friction contact area 18 may comprise a textured surface, forexample, having a plurality of ridges or raised protrusions 48 so thatthe surface is not smooth, or is relatively rough or course compared tothe surface of the duct contacting the web of packaging cushions. (FIG.7.) The protrusions may average from about 0.1 to about 0.8 inches inany of the length, width, and/or height dimensions. The friction forcecreated by the textured surface of the friction contact area may begreater than the friction force created by the same friction contactarea but without the textured surface (i.e., having a smooth surface).

Operation

In operating the conveyance system, the production machine 12manufactures a web of packaging cushions 20. The web passes beneath andcontacts the friction contact area 18 as the web of packaging cushionspasses from the production machine 12 to the duct entrance 28. Thecontact between the web of packaging cushions 20 and the frictioncontact area 18 creates a friction force (F₂) opposing the conveyanceforce (F₁) so that the conveyance force is not transmitted upstreamalong the web of packaging cushions to the production machine 12.

The web of packaging cushions 20 is drawn to duct entrance 28 byconverging with the motive fluid of air flow provided in the duct byblower 16. Duct entrance 28 is downstream from both the productionmachine 12 and the friction contact area 18. The air flow through theduct 14 applies a conveyance force (F₁) to the web to convey the web ofpackaging cushions 20 through the duct 14.

In operation, the manufacture of an additional length of the web ofpackaging cushions 20 from production machine 12 results in a temporaryreduction in the amount of surface area of the web that contacts thefriction contact area 18, so that the friction force (F₂) is reduced.This is believed to be because the additional length of the web ofpackaging cushions 20 increases the weight of the web between thefriction contact area 18 and the production machine 12 so that the webhangs lower to reduce the amount of surface area of the web thatcontacts the friction contact area 18. (See FIG. 6, which is shown inexaggerated configuration to enhance clarity). As a result, theconveyance force (F₁) overcomes the friction force (F₂) to advance theweb of packaging cushions downstream. The advancement length downstreamof the friction contact area 18 generally corresponds to the additionallength of the manufactured web. This result can repeat in relativelyquick succession so that the conveyance may operate fairly smoothly.

The system is useful to make and delivering webs of packaging cushionsto one or more locations remote from the production machine 12, whiledamping or averting the conveyance force from transmission upstreamalong the web of packaging cushions to production machine 12, therebyavoiding an adverse effect by the conveyance force on the operation ofproduction machine 12.

The following provides additional description of various embodiments ofthe invention.

A. A conveyance system for conveying a web of packaging cushions, thesystem comprising: (1) a production machine capable of manufacturing theweb of packaging cushions; (2) a duct downstream from the productionmachine, the duct having an entrance through which the web of packagingcushions can be drawn from the production machine; (3) a blower toprovide an air flow through the duct to apply a conveyance force to theweb for conveying the web of packaging cushions through the duct; and(4) a friction contact area downstream from the production machine andupstream from the duct entrance arranged so that (i) the web ofpackaging cushions passes beneath and contacts the friction contact areaas the web of packaging cushions passes from the production machine tothe duct entrance and (ii) the contact between the web of packagingcushions and the friction contact area creates a friction force opposingthe conveyance force so that the conveyance force is not transmittedalong the web of packaging cushions to the production machine.B. The system described in paragraph B wherein the friction contact areais arranged relative to the production machine and the duct entrance sothat the manufacture of an additional length of the web of packagingcushions results in a temporary reduction in the amount of surface areaof the web that contacts the friction contact area so that the frictionforce is reduced and the web of packaging cushions advances downstreamof the friction contact area in an amount corresponding to theadditional length.C. The system described in any of paragraphs A and B wherein thefriction contact area is arranged relative to the production machine andthe duct entrance so that the manufacture of an additional length of theweb of packaging cushions increases the weight of the web between thefriction contact area and the production machine so that: (i) the webhangs lower to reduce the amount of surface area of the web thatcontacts the friction contact area and (ii) the conveyance forceovercomes the friction force to advance the web of packaging cushionsdownstream.D. The system described in any of paragraphs A through C wherein: theweb of packaging cushions comprises a string of air-filled packagingcushions or a web of inflated rows; and the length in the machinedirection of the friction contact area is longer than the average lengthin the machine direction of the individual air-filled packaging cushionsor inflated rows that make up the web of packaging cushions.E. The system described in any of paragraphs A through D wherein theelevation of the duct entrance is above the elevation of the frictioncontact area taken at the lowest point of the friction contact area.F. The system described in any of paragraphs A through E wherein: theproduction machine defines a manufactured web outlet elevation fromwhich the manufactured web of packaging cushions passes; and the contactfriction area is below the manufactured web outlet elevation.G. The system described in any of paragraphs A through F wherein thefriction contact area is stationary.H. The system described in any of paragraphs A through G wherein thefriction contact area comprises primary a material selected from any of(1) an elastomer, such as any of those described herein, (2) a textilematerial comprising primarily any of the following: (i) natural fiber,such as primarily any of cotton or wool, or (ii) synthetic fiber, suchas primarily any of nylon, rayon, polyester, or aramid (such as Kevlar®brand aramid fiber), (3) leather, and (4) cork and/or comprisesprimarily material having a configuration selected from any of thefollowing: (a) woven, (b) non-woven, (c) tufted, and (d) hooked.I. The system described in any of paragraphs A through H wherein thefriction contact area comprises a mat, for example, a removably attachedmat.J. The system described in any of paragraphs A through I wherein thefriction contact area comprises a material having a textured surface toincrease the friction force compared to the same material having asmooth surface.K. The system described in any of paragraphs A through J wherein thefriction contact area comprises a woven material.L. The system described in any of paragraphs A through J wherein thefriction contact area comprises a non-woven material.M. The system described in any of paragraphs A through L wherein: thefriction contact area comprises primarily a first material and the ductcomprises primarily a second material; and the coefficient of frictionbetween the first material and the web of packaging cushions is greaterthan the coefficient of friction between the second material and the webof packaging cushions.

The above descriptions are those of preferred embodiments of theinvention. Various alterations and changes can be made without departingfrom the spirit and broader aspects of the invention as defined in theclaims, which are to be interpreted in accordance with the principles ofpatent law, including the doctrine of equivalents. Except in the claimsand the specific examples, or where otherwise expressly indicated, allnumerical quantities in this description indicating amounts of material,use conditions, and the like, are to be understood as modified by theword “about” in describing the broadest scope of the invention. Anyreference to an item in the disclosure or to an element in the claim inthe singular using the articles “a,” “an,” “the,” or “said” is not to beconstrued as limiting the item or element to the singular unlessexpressly so stated. The definitions and disclosures set forth in thepresent application control over any inconsistent definitions anddisclosures that may exist in an incorporated reference.

1. A conveyance system for conveying a web of packaging cushionscomprising a string of air-filled packaging cushions comprisingindividual air-filled packaging cushions or comprising individualinflated rows, the web of packaging cushions having an average length inthe machine direction of the individual air-filled packaging cushions orinflated rows that make up the web of packaging cushions, the systemcomprising: a production machine capable of manufacturing the web ofpackaging cushions; a duct downstream from the production machine, theduct having an entrance through which the web of packaging cushions canbe drawn from the production machine; a blower to provide an air flowthrough the duct to apply a conveyance force to the web for conveyingthe web of packaging cushions through the duct; and a friction contactarea having a length in the machine direction that is longer than theaverage length in the machine direction of the individual air-filledpackaging cushions or inflated rows that make up the web of packagingcushions, wherein the friction contact area is downstream from theproduction machine and upstream from the duct entrance and arranged sothat the web of packaging cushions passes beneath and contacts thefriction contact area as the web of packaging cushions passes from theproduction machine to the duct entrance, wherein: the friction contactarea comprises primarily a first material and the duct comprisesprimarily a second material; and the coefficient of friction between thefirst material and the web of packaging cushions is greater than thecoefficient of friction between the second material and the web ofpackaging cushions, whereby the contact between the web of packagingcushions and the friction contact area creates a friction force opposingthe conveyance force so that the conveyance force is not transmittedalong the web of packaging cushions to the production machine.
 2. Thesystem of claim 1 wherein the friction contact area is arranged relativeto the production machine and the duct entrance so that the manufactureof an additional length of the web of packaging cushions results in atemporary reduction in the amount of surface area of the web thatcontacts the friction contact area so that the friction force is reducedand the web of packaging cushions advances downstream of the frictioncontact area in an amount corresponding to the additional length.
 3. Thesystem of claim 1 wherein the friction contact area is arranged relativeto the production machine and the duct entrance so that the manufactureof an additional length of the web of packaging cushions increases theweight of the web between the friction contact area and the productionmachine so that: (i) the web hangs lower to reduce the amount of surfacearea of the web that contacts the friction contact area and (ii) theconveyance force overcomes the friction force to advance the web ofpackaging cushions downstream.
 4. A conveyance system for conveying aweb of packaging cushions the system comprising: a production machinecapable of manufacturing the web of packaging cushions; a ductdownstream from the production machine, the duct having an entrancethrough which the web of packaging cushions can be drawn from theproduction machine; a blower to provide an air flow through the duct toapply a conveyance force to the web for conveying the web of packagingcushions through the duct; and a friction contact area downstream fromthe production machine and upstream from the duct entrance arranged sothat (i) the web of packaging cushions passes beneath and contacts thefriction contact area as the web of packaging cushions passes from theproduction machine to the duct entrance and (ii) the contact between theweb of packaging cushions and the friction contact area creates afriction force opposing the conveyance force so that the conveyanceforce is not transmitted along the web of packaging cushions to theproduction machine, wherein the friction contact area comprises aremovably attached mat.
 5. The system of claim 1 wherein the elevationof the duct entrance is above the elevation of the friction contact areataken at the lowest point of the friction contact area.
 6. The system ofclaim 1 wherein: the production machine defines a manufactured weboutlet elevation from which the manufactured web of packaging cushionspasses; and the contact friction area is below the manufactured weboutlet elevation.
 7. The system of claim 1 wherein the friction contactarea is stationary.
 8. The system of claim 1 wherein the frictioncontact area comprises an elastomer.
 9. The system of claim 1 whereinthe friction contact area comprises a material having a textured surfaceto increase the friction force compared to the same material having asmooth surface.
 10. The system of claim 1 wherein the friction contactarea comprises a woven material.
 11. The system of claim 1 wherein thefriction contact area comprises a non-woven material.
 12. The system ofclaim 1 wherein the friction contact area comprises a removably attachedmat.
 13. The system of claim 4 wherein: the web of packaging cushionscomprises a string of air-filled packaging cushions comprisingindividual air-filled packaging cushions or comprising individualinflated rows, the web of packaging cushions having an average length inthe machine direction of the individual air-filled packaging cushions orinflated rows that make up the web of packaging cushions; and the lengthin the machine direction of the friction contact area is longer than theaverage length in the machine direction of the individual air-filledpackaging cushions or inflated rows that make up the web of packagingcushions.
 14. The system of claim 4 wherein: the friction contact areacomprises primarily a first material and the duct comprises primarily asecond material; and the coefficient of friction between the firstmaterial and the web of packaging cushions is greater than thecoefficient of friction between the second material and the web ofpackaging cushions.